Doctoral Dissertations

Abstract

"Microwave and millimeter wave imaging has shown tremendous utility in a wide variety of applications. These techniques are primarily based on measuring coherent electric field distribution on the target being imaged. Mechanically scanned systems are the simple and low cost solution in microwave imaging. However, these systems are typically bulky and slow. This dissertation presents a design for a 2D switched imaging array that utilizes modulated scattering techniques for spatial multiplexing of the signal. The system was designed to be compact, coherent, possessing high dynamic range, and capable of video frame rate imaging. Various aspects of the system design were optimized to achieve the design objectives. The 2D imaging system as designed and described in this dissertation utilized PIN diode loaded resonant elliptical slot antennas as array elements. The slot antennas allow for incorporating the switching into the antennas thus reducing the cost and size of the array. Furthermore, these slots are integrated in a simple low loss waveguide network. Moreover, the sensitivity and dynamic range of this system is improved by utilizing a custom designed heterodyne receiver and matched filter. This dissertation also presents an analysis on the properties of this system. The performance of the multiplexing scheme, the noise floor and the dynamic range of the receivers are investigated. Furthermore, sources of errors such as mutual coupling and array response dispersion are also investigated. Finally, utilizing this imaging system for various applications such as 2D electric field mapping, scatterer localization, and nondestructive imaging is demonstrated"--Abstract, Page iii.

Advisor(s)

Zoughi, R.

Committee Member(s)

DuBrof, Richard E.
Pommerenke, David
Stanley, R. Joe
OKeefe, Matt

Department(s)

Electrical and Computer Engineering

Degree Name

Ph. D. in Electrical Engineering

Sponsor(s)

United States. National Aeronautics and Space Administration

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2009

Pagination

xiii, 141 pages

Note about bibliography

Includes bibliographical references (pages 133-140).

Rights

© 2009 Mohammad Tayeb Ghasr, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Microwave imaging
Millimeter wave devices
Real-time control
Electric fields

Thesis Number

T 10041

Print OCLC #

847510168

Electronic OCLC #

847510269

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